New mdv discovery - QL Expert (an expert system shell)

[Chr$]

Thanks. I managed in the end after fannying about for an hour. It seems we have at least three different mdv image formats. I hope theres a bloody good reason.. otherwise

I *think* the .mdv files generated by mdump_task (which comes with Qemulator) are possibly closest to the original data structure as their size is usually around 115k, unless they have bad sectors, in which case it also saves alternate 'guessed' versions of those bad sectors and the files end up larger. Qemulator also seems happy with any of the .mdv formats you throw at it... yes, I think there are 3 different type

[XorA]

Q-Emulator format is just the data

QLAY format is also the gaps

mdump no idea Ive never seen the docs!

[Chr$]

Q-Emulator format is just the data

QLAY format is also the gaps

mdump no idea Ive never seen the docs!

mdump (the mdump_task program) is also by Daniele Terdina, author of Qemulator. So I think mdump is the same as Qemulator format? If so, then I think there is a third one but how it differs and where it comes from escapes me.

[Derek_Stewart]

Hi,

This is a great update, I used to have a Microdrive Cartridge of QL Expert, but it got corrupted.

I do not suppose that Francesco sril has the source code to QL Expert and Mega Toolbox?

If not they can be decompiled or disassembled.

I use MDI to convert MDV files from Q-emulator, this then works on QPC2. SMSQmulator, Q68, Q60, QXL...

[Martin_Head]

The QLAY image format is the closest to an actual microdrive cartridge. It contains all the preamble and inter sector data that is hidden from the user.
I don't think QLAY images work in the unregistered Qemulator.

The Qemulator/Mdump format has a special header (that starts with 'Mdv*Dump') that holds data about the dump. Then the actual sectors. First sectro 0, then the highest sector, counting down to 1.

The MDI format is a fixed 255 sectors of 534 bytes. Counting from sector 0 upwards. Any unused sectors are undefined.

As far as the three different image formats go. When I created the MDI format, I had no knowledge of the existence of any other image formats, (I had been away from the QL for a long time) And it was something I was doing just for myself. In fact the idea for the MDI driver came after I had converted all my MDV cartridges to MDI images.

I did toy with the idea once or twice, of trying to make the MDI driver support the other formats natively. But it's libel to create too much complication in the driver. When it's easy enough to just convert an image to or from the MDI format.

[pjw]

I downloaded qlexper2.mdv to have a quick peek. Knowing nothing of the
various formats at the time, I fired up mdidriver_cde (V1.06, I think) and
tried to mount the image. It returned Bad Name. So, naturally I went to
Dilwyn's to see if there was a later version, or any other mdv image
drivers. I found MDI Driver V1.10. (But after downloading it turned out to
be V1.08. So I updated to the latest.) Still no joy.

Then I tried some other .mdv files I had got from elsewhere and they all
showed up with Bad Name, except the four Psion mdvs that came with the MDI
driver. Loading these file into a hex editor told me there were differences
in the file formats: that's when I cottoned on that the difference between
.mdi and .mdv was not just in the name. So, after rummaging around I found
the MDI Convert utilities (they werent next to the MDI driver packages, so
easy to miss). It then became obvious that there were three different mdv
image formats..

However, I wasnt able to get MDIConvert2_bas to convert qlexper2.mdv to
an .mdi image. Is there a fourth type? I wondered..

Anyway, I finally figured that Mdv*Dump type images belonged to Q-emulator,
so I was able to open the file in that program and copy the contents to a
floppy image. Whew!

Im writing this to try to get across how messy all this is, mainly due to
the lack of proper documentation. Im not a QL novice, although pre-
millennial stuff is looking increasingly alien to me these days. All I
wanted was to have a quick peek and then get out. Perhaps I just missed the
memos..

The following rant is not aimed at any individual in particular. Im
grateful for all the wonderful stuff thats made for our darling beast and
its derivatives, including for stuff I wouldnt normally use myself, as it
all goes towards keeping the system alive!

It would be great if people could document their stuff, especially if they
create new "standards" that others may end up having to rely on. Im sure I
unknowingly sin too, so feel free to spank me right back should you come
across any dereliction on my part!

The other thing Id like to suggest is: don't create a new "standard" if
there already is an adequate one in existence - unless theres a very good
reason to. Do your research before embarking on such an undertaking. If you
need to improve on an existing standard, try to ensure your utility, or
whatever, is backwardly compatible.

And finally (not pertaining directly to anything here): Respect the
existing documented "systems standards". One of the banes of the QL back in
the day was people exploiting undocumented "features" of the OS or
hardware. Every new incompatibility or unnecessary divergence splits this
already marginal "community" further until we end up as a bunch of
unconnected islands.. and then nothing.

[Derek_Stewart]

Hi,

I loaded the qlexpr2_mdv file into QPC2 WIN1 QWA container.

Loaded MDI, which was v1.07 (need to up date)

entered:

CONVERT2_MDI "win1_exper2_mdv" to "mdi1_QLEXPERT_MDI"

MOUNT_MDI 1,"win1_QLEXPERT_MDI"
MDI_USE MDV
LRUN mdv1_boot

started up the QL Expert system in QPC2 in High Colour mode...

[tofro]

And?

Did someone change their QL configuration because of the program's recommendations?

[Tesla]

Thanks you Chris and Andrei, I always wished to own these pieces of software, especially the megatoolkit. Thanks to Francesco also, for his kindness.
I'll have fun tinkering with them tomorrow.
Good night.
Marco

[RWAP]

I attach a later version of the software from 1988 (v1.12) - as an mdv dump again